httppeer: remove redundant code to fetch capabilities

_fetchcaps() is called by httppeer.instance(), which is the only
instantiator of httppeer. Since _fetchcaps() always sets self._caps
and since 197d10e157ce removed the fallback for cases where the
remote doesn't support capabilities, we can remove some dead
code from httppeer.capabilities().

Differential Revision: https://phab.mercurial-scm.org/D2215

mercurial/httppeer.py

@@ -221,13 +221,9 b' class httppeer(wireproto.wirepeer):'
     # Begin of _basewirepeer interface.
 
     def capabilities(self):
-        if self._caps is None:
-            try:
-                self._fetchcaps()
-            except error.RepoError:
-                self._caps = set()
-            self.ui.debug('capabilities: %s\n' %
-                          (' '.join(self._caps or ['none'])))
+        # self._fetchcaps() should have been called as part of peer
+        # handshake. So self._caps should always be set.
+        assert self._caps is not None
         return self._caps
 
     # End of _basewirepeer interface.